Grade Dilution
Balance ore and nonzero-grade diluent on a mass basis; grades share one unit, and higher-grade diluent may increase rather than reduce blended grade.
Description
Dilution mixes ore with an additional material whose grade may be nonzero.
Dilution mixes ore with an additional material whose grade may be nonzero. A weighted mass balance determines the blended grade and separates the dilution fraction from the relative grade change.1
The tool returns dilutedGrade, diluentFractionOfMinedMass, relativeGradeChange. The computation uses supplied observations and parameters rather than acquiring measurements.
When to use Grade Dilution
Use this for the following task: Balance ore and nonzero-grade diluent on a mass basis; grades share one unit, and higher-grade diluent may increase rather than reduce blended grade. Prepare observations and calibration parameters on the same unit and reporting basis.
How to use Grade Dilution and understand its results
- Prepare the measured quantities and supplied model parameters. Match the units and align paired lists before calculating.
- Enter oreTonnes, oreGrade, diluentTonnes, diluentGrade according to the field table, then run the tool.
- Read dilutedGrade, diluentFractionOfMinedMass, relativeGradeChange. Use the calculation below to interpret the selected mean or the model’s signs, units and comparison flags.
- Review the supplied assumptions and calibration before comparing or reporting the result.
| Input field | Meaning | Value type and bounds | Requirement |
|---|---|---|---|
| oreTonnes | Ore tonnes | number | Required |
| oreGrade | Ore grade | number | Required |
| diluentTonnes | Diluent tonnes | number | Required |
| diluentGrade | Diluent grade | number | Required |
Use positive ore mass and grade and nonnegative diluent mass and grade. All masses and all grades must respectively share one unit.
blended grade = (oreMass×oreGrade+diluentMass×diluentGrade)/(oreMass+diluentMass) The symbols and boundary conditions refer to the supplied fields and the implementation described above.
| Output field | Meaning | Value type |
|---|---|---|
| dilutedGrade | Diluted grade | number |
| diluentFractionOfMinedMass | Diluent fraction of mined mass | number |
| relativeGradeChange | Relative grade change | number |
{
"input": {
"oreTonnes": 100,
"oreGrade": 2,
"diluentTonnes": 20,
"diluentGrade": 0.5
},
"output": {
"dilutedGrade": 1.75,
"diluentFractionOfMinedMass": 0.16666666666666666,
"relativeGradeChange": -0.125
}
}Limitations and assumptions
Higher-grade diluent can increase the blended grade. The tool does not estimate dilution geometry, recovery or assay uncertainty.
Numerical inputs must be finite. Input-shape and calculation checks do not establish measurement quality or the validity of a supplied calibration.
Alternative or Complementary methods
Choose Dilution Skin Thickness when you need its operation: Invert planar ore/diluent mass fraction to equal skin thickness on supplied faces; constant area/density, distinct from forward grade mixing. Choose Metal Content for the complementary operation: Calculate contained and recovered metal across dry-tonnage lots with grades in g/t; caller recovery fractions do not establish reserves or payable-metal terms.
Background reference: Material balance in mineral processing.
References
-
Material balance in mineral processing — NPTEL, Indian Institute of Technology Kanpur
Similar or alternative tools
- Dilution Skin Thickness
Invert planar ore/diluent mass fraction to equal skin thickness on supplied faces; constant area/density, distinct from forward grade mixing.
- Metal Content
Calculate contained and recovered metal across dry-tonnage lots with grades in g/t; caller recovery fractions do not establish reserves or payable-metal terms.